Robin Bowes;237384 Wrote: > radish wrote: > > basmac;237358 Wrote: > >> Here are the filesize numbers using iTunes for conversions > >> Internal Sony > >> Original aif 12058704 to m4a 4744079 back to aif 12058648 > >> External Pioneer > >> Original aif 12058704 to m4a 4738583 back to aif 12058648 > >> > >> I suppose I will leave it at that and assume I can't hear any > >> difference. > >> Just wanted to make sure I wasn't missing out on a few bits of > >> information, > >> > >> thanks > > > > The AIFF size is purely dependent on the length of the audio, > nothing > > else (an entirely silent file of the same length would also be > 12058704 > > bytes). The M4A size is dependent on content (because it's > compression > > ratio will vary with different input signals). Thus, what you have > > proven is that while both drives know exactly how long the track is > > (and agree on that) they disagree on what the audio data actually > is. > > This is exactly why people use things like EAC to get more reliable > > rips - consumer stuff like iTunes doesn't try to work around the > > differences in the hardware. One (possibly both) of your rips is > wrong, > > and there's no easy way to tell which. > > m4a can contain content other than audio (tags, images, etc.) so you > can't compare size directly. > > R.
Not in the general case, sure. But in this case we're using the same encoder, with (I assume) the same settings and metadata. Note also that the size difference is around 5k, that's quite a lot of metadata :) Of course, the OP should ensure that all the tags on the two m4a files match and that they both include the same cover art etc. Ideally, I'd suggest taking the raw AIFF files and running them through a command line m4a (or FLAC) encoder to remove any doubt. This can only really be settled once and for all by comparing the actual data in the AIFF files, if you can get the files to me I'd be happy to do such an analysis. -- radish ------------------------------------------------------------------------ radish's Profile: http://forums.slimdevices.com/member.php?userid=77 View this thread: http://forums.slimdevices.com/showthread.php?t=39564 _______________________________________________ ripping mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/ripping
